Recently, in the Internet communication market, paradigm has been changed from the existing megabit class to gigabit class. To keep pace with such a change in the Internet communication market, optical cables are used on the Internet lines in replacement of the existing copper cables.
In general, an optical cable for communication may have an optical cable mode that is classified into a single mode and a multi-mode. The single mode is a mode in which one light mode for guiding light in the optical cable exists and a long-distance transmission becomes possible, and the multi-mode is a mode in which several light modes for guiding light in the optical cable exist to facilitate short-distance transmission.
Although the optical cable in the multi-mode is used to rapidly transfer a large amount of information, it is general that the multi-mode optical cable has a double sheath structure in which an internal sheath having a large number of optical fibers mounted therein is mounted in an external sheath. Accordingly, the volume of the optical cable is greatly increased in proportion to the number of optical fibers mounted therein, and since the optical cable has the double sheath structure, the optical cable manufacturing process is complicated, and the manufacturing cost is increased.
Further, among optical cables in the related art, since an indoor optical cable installed in a building or an office is easily visible to the naked eye, it may be ill-matched with the surrounding environment or may deteriorate interior effects.